BSG: Daybreak Motivational Posters

[beccatoria]

Okay so this week I've been totally without work which is irritating since I went through such angst to clarify my damn hours (I'm supposed to have three days a week), but they're shifting me between projects and the new one was supposed to be kicking off Wednesday except apparently not so I'm stuck with no work 'til Monday. Which isn't exactly horrific except I'm broke and could have done with the cash and am now in a weird interim am-I-on-the-dole-or-aren't-I? situation. But whatever...y'all aren't exactly interested in that.

What y'all are probably interested in is the fact that, driven by boredom, and the inability of my mind to quite comprehend the hilarious fail of the post-Earthfall Daybreak stuff, I have responded in the only sane way I can think of.














Yay!

Honestly I feel a little mean about the Leetopia one and the Agriculture one because everyone seems to agree that Farmer!Gaius was the most moving thing in the episode, and I'm one of three people on the internet who really didn't see Lee's ending as a total tragedy. I mean, the part where he got far more idealistic than smart and threw everything INTO THE SUN was a tragedy, sure. But look at him in that field! He's so happy! And kind of...free. Looking forward. Sure it would have been nice if that had happened with a metaphorical moving away from Kara and his Dad rather than them turning into invisible pigeons and necrophiliac hermits, but whatever, I WANTED TO HUGGLE HIM.

Ahem.

Redacted.

Comments

[raincitygirl.livejournal.com]

But can I ask a question (to make sure I'm understanding correctly) because you've actually read about this! If that woman had sons and then those sons had daughters, that'd still be okay, right? Because those granddaughters would be getting their mtDNA from their maternal grandmother?

Similarly I wasn't aware it had to happen in the first generation? So in theory, Jane the Colonial could have a direct line of mother-daughter descent for six generations, but then that girl - her last matrilineal descendant, has only sons/no children at all?

Nope. Well, the kids would be fine, but the mtDNA lineage would have died out. Which is not to say that the grandmother's actual lineage would've died out, but it couldn't be tracked genetically anymore. Because everything except Y chromosomes (in men) and mtDNA (in everybody) gets reshuffled every generation, there's no way of tracking anything except mother's-mother's-mother's-mother's-mother and father's-father's-father's-father beyond a few generations.

If scientists dug up my great-great-grandmother on my mother's side and were lucky enough to find usable DNA in the remains, they could establish that we were related in two ways: through mtDNA (actually, mtDNA probably wouldn't be very useful, because four generations isn't very long by mtDNA standards), and through regular genetic testing. If you go much further back than that, even if you have usable DNA, regular genetic testing won't tell you much because the reshuffling each generation has diluted the genetic inheritance so much. And that reshuffling (which is good for us, because it allows for beneficial mutations etc. We're not just clones of the previous generation), is why geneticists have glommed onto mtDNA and Y chromosomes, because they don't get reshuffled.

But it's very easy for a lineage to die out, because this stuff is, as you say, a genetic lottery. And it only takes one generation. With my maternal great-great-grandmother, clearly she had at least one daughter (my great-grandmother, who gave birth to my maternal grandmother). My maternal grandmother had two daughters: my mother and my aunt. But for mtDNA purposes, my aunt doesn't count because she has no daughters, any more than my uncles count, even though they both have daughters. The lineage goes from my maternal grandmother to my mom, and then to my sister and me. But if neither my sister nor I have children, or we only have sons, game over for the mtDNA lineage. My little brother and his girlfriend could produce hundreds of fat babies (and make my mom very happy, because she desperately wants to be a grandmother, and my lack of maternal instinct frustrates her). But none of those fat babies would have my mom's mtDNA.

So yeah, mtDNA can die out in one generation. However, it's not always immediately obvious that it will die out. From a genetic POV, until my sister and I have both hit menopause, there's always the possibility that we could have daughters. Or my sister could have a whole whack of daughters, but none of them survive to/choose to pass on their genes (because they're just as un-maternal as me). The only way you know for sure that a lineage will definitely die out is if a woman has been through menopause, and of her grown-up children, only sons have survived to adulthood.

[beccatoria.livejournal.com]

Okay thanks, that's cool and pretty much what I thought. Other women from that time frame might well have living descendants, but there is simply no genetic way of confirming that/tracking them.